1. Field of the Invention
The present invention relates to a method and apparatus for evaluating performance of welded joints.
2. Description of the Prior Art
An evaluation of the performance of welded butt joints has been accomplished by use of standard tensile specimens (ISO or ASTM), rectangular plaques and T-shape elements (ultrasonic welding specimens, American Welding Society G1.2). After welding, the effectiveness of the joints is tested using standard test practices. The use of standard tensile specimens (ISO or ASTM), rectangular plaques and T-shape elements has advantages, among which are the availability of injection-molded plaques, and convenient configuration and size of test specimens for easy machining operations for the specimen preparations. A problem encountered with use of standard tensile specimens (ISO or ASTM), rectangular plaques and T-shape elements is the limitation that these specimens may only be successfully welded using specially prepared, small welding machines. Only one such small size linear vibration welding machine is available commercially at this time. Such a machine, designated Model M-102, is manufactured by Branson Ultrsonic, Germany. When a company is equipped with a mid or large welding machine for welding midsize and large parts, such as lawn mower housings and air intake manifolds, it is very hard to evaluate tensile properties of the joints following the ASTM or ISO procedures. In such circumstances, these specimens are too small for the machine size, and the clamp pressure will be too high. Mechanical performance of thus-welded specimens will often not represent true weld strength property of the material being evaluated.
It would be desirable to provide a method and articles for evaluating welded joints which would overcome the above mentioned shortcomings.